memory_alphafandomcom-20200223-history
Rocket
A Rocket was a form of spacecraft propulsion, usually used when a society began the early stages of space flight. It was simple and reliable, and could be constructed from easily available materials. Rocket engines could also be used in a wide range of other applications, from fireworks to weapons. Basic principles of operation The most common form of rocket involved burning a fuel in an oxidiser and ducting the exhaust gases in the opposite direction of the intended thrust. A rocket was effective in an atmosphere, but was at its most efficient in hard vacuum. Types of rocket There were three basic forms of rocket: * Solid-fuelled rockets. These were invented in Chinese prehistory. They are very simple to build and use, but once they have been ignited they cannot be throttled or extinguished, which limits their use as spacecraft. During the 20th and 21st centuries, these were mostly used as auxillary boosters for heavy launch vehicles. * Liquid-fuelled rockets. Developed in the early 20th Century, these were the basis of the first launch vehicles, and propelled the craft that initially explored the Solar System, including such famous spacecraft as Ranger 3 (TOS: The Cage) and the Apollo missions (TOS: Tomorrow is Yesterday, VOY: Nightingale). They were versatile and efficient, but could be complex and expensive to build, and if poorly maintained could be prone to catastrophic failures (i.e. explosions). * Nuclear-fuelled rockets. These operated by using a nuclear reaction to heat up some fluid, which was then ejected at high speed. Capable of higher speeds than other types or rocket, nuclear rocket engines were not used until the mid-21st century. Fusion-powered impulse engines operate on similar principles, but their reaction mass is provided by their own exhaust products, and they therefore constitute a separate type of propulsion. Drawbacks Rockets are rarely used in societies which have attained Warp and/or impulse travel, although they occasionally find uses in small applications such as boosters for gravity boots (Star Trek V: The Final Frontier). A rocket has a limited maximum speed - it can only travel as fast as exhaust gases are ejected, which in practical terms means that a rocket cannot go faster than about 0.25c (i.e. one quarter of the Speed of Light). Since the force of a rocket depends on the number, speed and mass of the exhaust gas particles, rockets are also impractical for propelling large vehicles, in contrast to fusion-powered impulse engines (especially those with continuum distortion coils, such as those found aboard a Galaxy class starship). Significant Rockets Due to their simplicity, rockets are the most common form of propulsion for a society's first space flights. Rocket-powered spacecraft are therefore not an uncommon sight in the galaxy at large, although they are generally indicative of a low technological level. The Enterprise, for example, encountered a rocket propelled missile in 2268(TOS: Patterns of Force; the Enterprise-D likewise came across rocket propelled spacecraft several times (e.g TNG: The Outrageous Okona). Probably the most famous rocket in Earth history is the Phoenix, Zefram Cochrane's first warp-powered spacecraft. Although the Phoenix itself was powered by an early warp drive, it had to be boosted into Earth orbit by a chemical rocket (which was, at that time, the only practical launch system available). The booster Cochrane used for his historic flight was modified from a Titan V nuclear missile. (Star Trek: First Contact)